The proposed research has two major long-term goals. The first is to investigate the development of children's understanding and use of maps. Maps and other graphic representations are critical to human communication, travel, and education, but researchers have only recently begun to investigate how the ability to use them develops. The second long-term goal is to use children's understanding of maps as a window onto basic processes in the development of spatial cognition. How children represent and communicate spatial relations is a topic of both classic and current interest in psychology as well as in other disciplines, such as geography. Studying children's use of maps can provide important new perspectives on these issues. In addition, providing basic information about spatial cognition and its development is relevant to understanding and treating several disorders, such as Williams Syndrome and agnosia. Two characteristics of maps make them particularly relevant to research in cognitive development. First, in a general sense, all maps are symbols; the small-scale representation stands for something or some place in the world. Second, in a more specific sense, maps are also spatial representations; they communicate the locations of places and the relations among these locations. Consequently, maps have also proved to be useful tools for studying basic issues in the development of spatial cognition, such as how children encode spatial configurations. Specifically, the aims will be (I) to investigate the development of the ability to use the scale relation between a map and the space that it represents and (2) to determine whether and under what conditions children can mentally represent an entire configuration of objects. The subjects will be healthy 4-year-olds, 6-year-olds, and adults. The method, scaling and reconstruction, requires that subjects first memorize a simple map that will show the locations of objects in an otherwise empty room. Subjects then will be asked to reconstruct the configurations, from memory, in the room. This method can be particularly informative. Children must accurately represent the information depicted on the maps and they must transform the spatial information to the larger scale of the room. To determine where to place each object, children must somehow relate the small-scale map to the larger scale room. They need to know, for example, that the positions of individual objects on the maps corresponds to the positions that should exist in the larger room. Experiment I will address how the presence of fixed landmarks affects the accuracy of children's reconstructions; Experiments 2 and 3 will determine whether and how children's understanding of the relation between the map and the room can be enhanced. Analyses will focus on (a) whether subjects preserve the overall configuration of objects, and (b) whether they place the objects close to the correct locations.